Update colander from 1.3.3 to 1.4

Author: pyup-bot

{{cookiecutter.project_slug}}/requirements.txt

@@ -2,7 +2,7 @@ alabaster==0.7.10
 apipkg==1.4
 appdirs==1.4.3
 Babel==2.5.0
-colander==1.3.3
+colander==1.4
 configparser==3.5.0
 coverage==4.4.1
 docutils==0.13.1